Basic support for deleting items, and editing meshlike items

src/bonsai/bonsai/bim/import_ifc.py

@@ -1370,46 +1370,7 @@ class IfcImporter:
                 verts = geometry.verts
                 mesh["has_cartesian_point_offset"] = False
 
-            if geometry.faces:
+            return tool.Loader.convert_geometry_to_mesh(geometry, mesh, verts=verts)
-                num_vertices = len(verts) // 3
-                total_faces = len(geometry.faces)
-                loop_start = range(0, total_faces, 3)
-                num_loops = total_faces // 3
-                loop_total = [3] * num_loops
-                num_vertex_indices = len(geometry.faces)
-
-                # See bug 3546
-                # ios_edges holds true edges that aren't triangulated.
-                #
-                # we do `.tolist()` because Blender can't assign `np.int32` to it's custom attributes
-                mesh["ios_edges"] = list(set(tuple(e) for e in ifcopenshell.util.shape.get_edges(geometry).tolist()))
-                mesh["ios_item_ids"] = ifcopenshell.util.shape.get_representation_item_ids(geometry).tolist()
-
-                mesh.vertices.add(num_vertices)
-                mesh.vertices.foreach_set("co", verts)
-                mesh.loops.add(num_vertex_indices)
-                mesh.loops.foreach_set("vertex_index", geometry.faces)
-                mesh.polygons.add(num_loops)
-                mesh.polygons.foreach_set("loop_start", loop_start)
-                mesh.polygons.foreach_set("loop_total", loop_total)
-                mesh.polygons.foreach_set("use_smooth", [0] * total_faces)
-                mesh.update()
-
-                rep_str: str = geometry.id
-                if "openings" not in rep_str:
-                    rep_id = rep_str.split("-", 1)[0]
-                    rep = self.file.by_id(int(rep_id))
-                    tool.Loader.load_indexed_colour_map(rep, mesh)
-            else:
-                e = geometry.edges
-                v = verts
-                vertices = [[v[i], v[i + 1], v[i + 2]] for i in range(0, len(v), 3)]
-                edges = [[e[i], e[i + 1]] for i in range(0, len(e), 2)]
-                mesh.from_pydata(vertices, edges, [])
-
-            mesh["ios_materials"] = [m.instance_id() for m in geometry.materials]
-            mesh["ios_material_ids"] = geometry.material_ids
-            return mesh
         except:
             self.ifc_import_settings.logger.error("Could not create mesh for %s", element)
             import traceback

src/bonsai/bonsai/bim/module/geometry/data.py

@@ -47,18 +47,18 @@ class ViewportData:
     @classmethod
     def mode(cls):
         obj = bpy.context.active_object
-        obj_mode = [("OBJECT", "IFC Object Mode", "", "OBJECT_DATAMODE", 0)]
+        modes = [
-        mesh_modes = [
             ("OBJECT", "IFC Object Mode", "", "OBJECT_DATAMODE", 0),
-            ("EDIT", "IFC Edit Mode", "", "EDITMODE_HLT", 1),
+            ("ITEM", "IFC Item Mode", "", "MESH_DATA", 1),
         ]
         if (
             not obj
             or not tool.Blender.is_editable(obj)
             or ((element := tool.Ifc.get_entity(obj)) and tool.Geometry.is_locked(element))
         ):
-            return obj_mode
+            return modes
-        return mesh_modes
+        modes.append(("EDIT", "IFC Edit Mode", "", "EDITMODE_HLT", 2))
+        return modes
 
 
 class RepresentationsData:

src/bonsai/bonsai/bim/module/geometry/decorator.py

@@ -18,7 +18,6 @@
 
 import blf
 import gpu
-import json
 import bmesh
 import bonsai.tool as tool
 from bpy.types import SpaceView3D
@@ -125,9 +124,25 @@ class ItemDecorator:
                     edges = unselected_edges
                     verts = unselected_verts
                 i = len(verts)
-                edges.extend([[ei + i for ei in e] for e in json.loads(item.edges)])
+
                 matrix_world = obj.matrix_world
-                verts.extend([matrix_world @ Vector(v) for v in json.loads(item.verts)])
+                bbox_verts = [matrix_world @ Vector(co) for co in obj.bound_box]
+                bbox_edges = [
+                    (0 + i, 3 + i),
+                    (3 + i, 7 + i),
+                    (7 + i, 4 + i),
+                    (4 + i, 0 + i),
+                    (0 + i, 1 + i),
+                    (3 + i, 2 + i),
+                    (7 + i, 6 + i),
+                    (4 + i, 5 + i),
+                    (1 + i, 2 + i),
+                    (2 + i, 6 + i),
+                    (6 + i, 5 + i),
+                    (5 + i, 1 + i),
+                ]
+                edges.extend(bbox_edges)
+                verts.extend(bbox_verts)
 
         if unselected_verts:
             self.draw_batch("LINES", unselected_verts, transparent_color(unselected_elements_color), unselected_edges)

src/bonsai/bonsai/bim/module/geometry/operator.py

@@ -16,12 +16,11 @@
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
 
+import re
 import bpy
 import bmesh
 import logging
 import numpy as np
-import json
-import re
 import ifcopenshell
 import ifcopenshell.util.unit
 import ifcopenshell.util.element
@@ -637,6 +636,8 @@ class OverrideDelete(bpy.types.Operator):
                     self.report({"INFO"}, "Elements that are part of an array cannot be deleted.")
                     return {"FINISHED"}
                 tool.Geometry.delete_ifc_object(obj)
+            elif tool.Geometry.is_representation_item(obj):
+                tool.Geometry.delete_ifc_item(obj)
             else:
                 bpy.data.objects.remove(obj)
 
@@ -1591,6 +1592,12 @@ class OverrideModeSetEdit(bpy.types.Operator, tool.Ifc.Operator):
                 return bpy.ops.bim.enable_editing_boundary_geometry()
 
         for obj in selected_objs:
+            if obj == context.scene.BIMGeometryProperties.representation_obj:
+                self.report({"ERROR"}, f"Element '{obj.name}' is in item mode and cannot be edited directly.")
+                obj.select_set(False)
+                continue
+            if tool.Geometry.is_representation_item(obj):
+                return self.enable_editing_representation_item(context, obj)
             if not tool.Blender.is_editable(obj):
                 self.report({"INFO"}, f"Object cannot be edited: {obj.name}")
                 obj.select_set(False)
@@ -1694,6 +1701,21 @@ class OverrideModeSetEdit(bpy.types.Operator, tool.Ifc.Operator):
         context.view_layer.objects.active = active_obj
         return {"FINISHED"}
 
+    def enable_editing_representation_item(self, context, obj):
+        item = tool.Ifc.get().by_id(obj.data.BIMMeshProperties.ifc_definition_id)
+        if tool.Geometry.is_meshlike_item(item):
+            tool.Blender.select_and_activate_single_object(context, obj)
+            obj.data.BIMMeshProperties.mesh_checksum = tool.Geometry.get_mesh_checksum(obj.data)
+            if tool.Blender.toggle_edit_mode(context) == {"CANCELLED"}:
+                return {"CANCELLED"}
+            context.scene.BIMGeometryProperties.is_changing_mode = True
+            if context.scene.BIMGeometryProperties.mode != "EDIT":
+                context.scene.BIMGeometryProperties.mode = "EDIT"
+            context.scene.BIMGeometryProperties.is_changing_mode = False
+            return {"FINISHED"}
+        else:
+            self.report({"INFO"}, f"Editing {item.is_a()} geometry is not supported")
+
     def invoke(self, context, event):
         return IfcStore.execute_ifc_operator(self, context, is_invoke=True)
 
@@ -1716,28 +1738,49 @@ class OverrideModeSetObject(bpy.types.Operator, tool.Ifc.Operator):
             if self.should_save:
                 bpy.ops.bim.update_representation(obj=obj.name, ifc_representation_class="")
                 if getattr(tool.Ifc.get_entity(obj), "HasOpenings", False):
-                    self.reload_representation(obj)
+                    tool.Geometry.reload_representation(obj)
             else:
-                self.reload_representation(obj)
+                tool.Geometry.reload_representation(obj)
             tool.Ifc.finish_edit(obj)
 
         for obj in self.unchanged_objs_with_openings:
-            self.reload_representation(obj)
+            tool.Geometry.reload_representation(obj)
             tool.Ifc.finish_edit(obj)
         return {"FINISHED"}
 
-    def reload_representation(self, obj):
+    def edit_representation_item(self, obj):
-        representation = tool.Ifc.get().by_id(obj.data.BIMMeshProperties.ifc_definition_id)
+        item = tool.Ifc.get().by_id(obj.data.BIMMeshProperties.ifc_definition_id)
-        core.switch_representation(
+        if tool.Geometry.is_meshlike_item(item):
-            tool.Ifc,
+            if tool.Geometry.has_geometric_data(obj) and obj.data.polygons:
-            tool.Geometry,
+                if obj.data.BIMMeshProperties.mesh_checksum == tool.Geometry.get_mesh_checksum(obj.data):
-            obj=obj,
+                    return {"FINISHED"}
-            representation=representation,
+                builder = ifcopenshell.util.shape_builder.ShapeBuilder(tool.Ifc.get())
-            should_reload=True,
+                unit_scale = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
-            is_global=True,
+                verts = [v.co / unit_scale for v in obj.data.vertices]
-            should_sync_changes_first=False,
+                faces = [p.vertices[:] for p in obj.data.polygons]
-            apply_openings=True,
+                if item.is_a("IfcAdvancedBrep"):
-        )
+                    new_item = builder.faceted_brep(verts, faces)
+                else:
+                    new_item = builder.mesh(verts, faces)
+                for inverse in tool.Ifc.get().get_inverse(item):
+                    ifcopenshell.util.element.replace_attribute(inverse, item, new_item)
+                ifcopenshell.util.element.remove_deep2(tool.Ifc.get(), item)
+                obj.data.BIMMeshProperties.ifc_definition_id = new_item.id()
+                tool.Geometry.reload_representation(bpy.context.scene.BIMGeometryProperties.representation_obj)
+                return {"FINISHED"}
+            else:
+                self.reload_item(obj)
+                return {"FINISHED"}
+        return {"FINISHED"}
+
+    def reload_item(self, obj):
+        tool.Loader.settings.contexts = ifcopenshell.util.representation.get_prioritised_contexts(tool.Ifc.get())
+        tool.Loader.settings.context_settings = tool.Loader.create_settings()
+        tool.Loader.settings.gross_context_settings = tool.Loader.create_settings(is_gross=True)
+        item = tool.Ifc.get().by_id(obj.data.BIMMeshProperties.ifc_definition_id)
+        geometry = tool.Loader.create_generic_shape(item)
+        obj.data.clear_geometry()
+        tool.Loader.convert_geometry_to_mesh(geometry, obj.data)
 
     def invoke(self, context, event):
         return IfcStore.execute_ifc_operator(self, context, is_invoke=True)
@@ -1750,6 +1793,10 @@ class OverrideModeSetObject(bpy.types.Operator, tool.Ifc.Operator):
         bpy.ops.object.mode_set(mode="EDIT", toggle=True)
 
         context.scene.BIMGeometryProperties.is_changing_mode = True
+        if context.scene.BIMGeometryProperties.representation_obj:
+            if context.scene.BIMGeometryProperties.mode != "ITEM":
+                context.scene.BIMGeometryProperties.mode = "ITEM"
+        else:
             if context.scene.BIMGeometryProperties.mode != "OBJECT":
                 context.scene.BIMGeometryProperties.mode = "OBJECT"
         context.scene.BIMGeometryProperties.is_changing_mode = False
@@ -1761,6 +1808,8 @@ class OverrideModeSetObject(bpy.types.Operator, tool.Ifc.Operator):
             element = tool.Ifc.get_entity(context.active_object)
             if element and element.is_a("IfcRelSpaceBoundary"):
                 return bpy.ops.bim.edit_boundary_geometry()
+            elif tool.Geometry.is_representation_item(context.active_object):
+                return self.edit_representation_item(context.active_object)
 
         objs = context.selected_objects or [context.active_object]
 
@@ -1909,7 +1958,6 @@ class RemoveRepresentationItem(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_representation_item"
     bl_label = "Remove Representation Item"
     bl_options = {"REGISTER", "UNDO"}
-
     representation_item_id: bpy.props.IntProperty()
 
     @classmethod
@@ -1923,7 +1971,6 @@ class RemoveRepresentationItem(bpy.types.Operator, tool.Ifc.Operator):
 
     def _execute(self, context):
         obj = context.active_object
-        props = obj.BIMGeometryProperties
         ifc_file = tool.Ifc.get()
 
         representation_item = ifc_file.by_id(self.representation_item_id)
@@ -2217,7 +2264,7 @@ class RemoveRepresentationItemFromShapeAspect(bpy.types.Operator, tool.Ifc.Opera
 
 
 class ImportRepresentationItems(bpy.types.Operator, tool.Ifc.Operator):
-    bl_idname = "bim.xxx_import_representation_items"
+    bl_idname = "bim.import_representation_items"
     bl_label = "Import Representation Items"
     bl_options = {"REGISTER", "UNDO"}
 
@@ -2225,85 +2272,38 @@ class ImportRepresentationItems(bpy.types.Operator, tool.Ifc.Operator):
         obj = context.active_object
         tool.Geometry.apply_item_ids_as_vertex_groups(obj)
         tool.Geometry.dissolve_triangulated_edges(obj)
-        bm_dict = self.separate_faces_by_vertex_group(obj)
-        # bm_dict = self.separate_faces_by_id(obj)
         props = context.scene.BIMGeometryProperties
-        props.item_objs.clear()
+        props.representation_obj = obj
+        tool.Geometry.lock_object(obj)
 
-        for item_id, bm in bm_dict.items():
+        context.scene.BIMGeometryProperties.is_changing_mode = True
-            item_mesh = bpy.data.meshes.new(f"mesh_id_{item_id}")
+        if context.scene.BIMGeometryProperties.mode != "ITEM":
-            bm.to_mesh(item_mesh)
+            context.scene.BIMGeometryProperties.mode = "ITEM"
-            bm.free()
+        context.scene.BIMGeometryProperties.is_changing_mode = False
 
+        item_ids = set()
+        for vgroup in obj.vertex_groups:
+            if vgroup.name.startswith("ios_item_id_"):
+                item_ids.add(int(vgroup.name.split("_")[-1]))
+
+        tool.Loader.settings.contexts = ifcopenshell.util.representation.get_prioritised_contexts(tool.Ifc.get())
+        tool.Loader.settings.context_settings = tool.Loader.create_settings()
+        tool.Loader.settings.gross_context_settings = tool.Loader.create_settings(is_gross=True)
+
+        for item_id in item_ids:
             item = tool.Ifc.get().by_id(item_id)
+            item_mesh = bpy.data.meshes.new(f"Item/{item.is_a()}/{item_id}")
+            item_mesh.BIMMeshProperties.ifc_definition_id = item_id
+            geometry = tool.Loader.create_generic_shape(item)
+            tool.Loader.convert_geometry_to_mesh(geometry, item_mesh)
+
             item_obj = bpy.data.objects.new(f"Item/{item.is_a()}/{item_id}", item_mesh)
             item_obj.matrix_world = obj.matrix_world
             item_obj.show_in_front = True
             bpy.context.collection.objects.link(item_obj)
 
+            if tool.Geometry.is_meshlike_item(item):
+                tool.Geometry.lock_object(item_obj)
+
             new = props.item_objs.add()
             new.obj = item_obj
-
-            verts = [list(co) for co in item_obj.bound_box]
-            edges = [(0, 3), (3, 7), (7, 4), (4, 0), (0, 1), (3, 2), (7, 6), (4, 5), (1, 2), (2, 6), (6, 5), (5, 1)]
-            new.verts = json.dumps(verts)
-            new.edges = json.dumps(edges)
-
-    def separate_faces_by_id(self, obj):
-        mesh = obj.data
-        bm = bmesh.new()
-        bm.from_mesh(mesh)
-        results = {}
-        face_ids = mesh["ios_item_ids"]
-        unique_ids = set(face_ids)
-
-        for item_id in unique_ids:
-            item_bm = bmesh.new()
-            for face, face_id in zip(bm.faces, face_ids):
-                if face_id == item_id:
-                    # Copy the face and its vertices into the new BMesh
-                    new_face_verts = [item_bm.verts.new(v.co) for v in face.verts]
-                    item_bm.faces.new(new_face_verts)
-            item_bm.verts.ensure_lookup_table()
-            item_bm.faces.ensure_lookup_table()
-            results[item_id] = item_bm
-
-        return results
-
-    def separate_faces_by_vertex_group(self, obj):
-        mesh = obj.data
-        bm = bmesh.new()
-        bm.from_mesh(mesh)
-
-        # Ensure the bmesh has up-to-date vertex weights (vertex groups)
-        bm.verts.layers.deform.verify()
-
-        results = {}
-        for vgroup in obj.vertex_groups:
-            group_bm = bmesh.new()
-            deform_layer = bm.verts.layers.deform.active
-
-            # Iterate over the faces and check if all vertices of the face belong to the vertex group
-            for face in bm.faces:
-                face_in_group = True
-                for vert in face.verts:
-                    # Get the vertex groups the vertex belongs to
-                    deform = vert[deform_layer]
-
-                    # If this vertex does not belong to the current vertex group, mark the face as outside the group
-                    if vgroup.index not in deform:
-                        face_in_group = False
-                        break
-
-                # If all vertices of the face belong to the current vertex group, add the face to the new BMesh
-                if face_in_group:
-                    new_face_verts = [group_bm.verts.new(v.co) for v in face.verts]
-                    group_bm.faces.new(new_face_verts)
-
-            # Ensure the mesh is valid and doesn't have duplicate elements
-            group_bm.verts.ensure_lookup_table()
-            group_bm.faces.ensure_lookup_table()
-
-            results[int(vgroup.name.split("_")[3])] = group_bm
-
-        return results

src/bonsai/bonsai/bim/module/geometry/prop.py

@@ -43,11 +43,23 @@ def update_mode(self, context):
     if self.is_changing_mode:
         return
     if self.mode == "OBJECT":
+        if self.representation_obj:
+            tool.Geometry.unlock_object(self.representation_obj)
+        self.representation_obj = None
         bpy.ops.bim.override_mode_set_object("INVOKE_DEFAULT")
+    elif self.mode == "ITEM":
+        bpy.ops.bim.import_representation_items()
     elif self.mode == "EDIT":
         bpy.ops.bim.override_mode_set_edit("INVOKE_DEFAULT")
 
 
+def update_representation_obj(self, context):
+    for item_obj in self.item_objs:
+        if item_obj.obj:
+            bpy.data.objects.remove(item_obj.obj)
+    self.item_objs.clear()
+
+
 def get_mode(self, context):
     if not ViewportData.is_loaded:
         ViewportData.load()
@@ -147,6 +159,7 @@ class BIMGeometryProperties(PropertyGroup):
     should_force_triangulation: BoolProperty(name="Force Triangulation", default=False)
     is_changing_mode: BoolProperty(name="Is Changing Mode", default=False)
     mode: EnumProperty(items=get_mode, name="IFC Interaction Mode", update=update_mode)
+    representation_obj: PointerProperty(name="Representation Object", type=bpy.types.Object, update=update_representation_obj)
     item_objs: CollectionProperty(name="Item Objects", type=RepresentationItemObject)
 
     def is_object_valid_for_representation_copy(self, obj: bpy.types.Object) -> bool:

src/bonsai/bonsai/bim/ui.py

@@ -456,7 +456,11 @@ class BIM_PT_tabs(Panel):
             op.uri = "https://docs.bonsaibim.org/guides/troubleshooting.html#saving-and-loading-blend-files"
             row.operator("bim.close_blend_warning", text="", icon="CANCEL")
 
-        if not context.mode.startswith(context.scene.BIMGeometryProperties.mode):
+        if context.mode == "OBJECT" and context.scene.BIMGeometryProperties.mode in ("OBJECT", "ITEM"):
+            pass
+        elif context.mode.startswith("EDIT") and context.scene.BIMGeometryProperties.mode == "EDIT":
+            pass
+        else:
             box = self.layout.box()
             box.alert = True
             row = box.row(align=True)

src/bonsai/bonsai/tool/geometry.py

@@ -22,6 +22,7 @@ import struct
 import hashlib
 import logging
 import numpy as np
+import multiprocessing
 import ifcopenshell
 import ifcopenshell.api
 import ifcopenshell.api.grid
@@ -114,6 +115,20 @@ class Geometry(bonsai.core.tool.Geometry):
         obj.lock_location = (False, False, False)
         obj.lock_rotation = (False, False, False)
 
+    @classmethod
+    def delete_ifc_item(cls, obj: bpy.types.Object) -> None:
+        props = bpy.context.scene.BIMGeometryProperties
+        if len(props.item_objs) == 1:
+            return
+        for i, item_obj in enumerate(props.item_objs):
+            if item_obj.obj == obj:
+                props.item_objs.remove(i)
+                break
+        item = tool.Ifc.get().by_id(obj.data.BIMMeshProperties.ifc_definition_id)
+        cls.remove_representation_item(item)
+        cls.reload_representation(props.representation_obj)
+        bpy.data.objects.remove(obj)
+
     @classmethod
     def delete_ifc_object(cls, obj: bpy.types.Object) -> None:
         element = tool.Ifc.get_entity(obj)
@@ -184,6 +199,8 @@ class Geometry(bonsai.core.tool.Geometry):
                 bonsai.core.spatial.import_spatial_decomposition(tool.Spatial)
         try:
             obj.name
+            if bpy.context.scene.BIMGeometryProperties.representation_obj == obj:
+                bpy.context.scene.BIMGeometryProperties.representation_obj = None
             bpy.data.objects.remove(obj)
         except:
             pass
@@ -401,6 +418,11 @@ class Geometry(bonsai.core.tool.Geometry):
         if obj.data and hasattr(obj.data, "BIMMeshProperties") and obj.data.BIMMeshProperties.ifc_definition_id:
             return tool.Ifc.get().by_id(obj.data.BIMMeshProperties.ifc_definition_id)
 
+    @classmethod
+    def get_data_representation(cls, data: bpy.types.Mesh) -> ifcopenshell.entity_instance | None:
+        if hasattr(data, "BIMMeshProperties") and data.BIMMeshProperties.ifc_definition_id:
+            return tool.Ifc.get().by_id(data.BIMMeshProperties.ifc_definition_id)
+
     @classmethod
     def get_active_representation_context(cls, obj: bpy.types.Object) -> ifcopenshell.entity_instance:
         active_representation = tool.Geometry.get_active_representation(obj)
@@ -806,6 +828,10 @@ class Geometry(bonsai.core.tool.Geometry):
             return True
         return False
 
+    @classmethod
+    def is_meshlike_item(cls, item: ifcopenshell.entity_instance) -> bool:
+        return item.is_a("IfcTessellatedItem") or item.is_a("IfcManifoldSolidBrep")
+
     @classmethod
     def is_profile_based(cls, data: bpy.types.Mesh) -> bool:
         return data.BIMMeshProperties.subshape_type == "PROFILE"
@@ -816,6 +842,14 @@ class Geometry(bonsai.core.tool.Geometry):
             "SweptSolid",
         )
 
+    @classmethod
+    def is_representation_item(cls, obj: bpy.types.Object) -> bool:
+        return (
+            obj.data
+            and (ifc_id := obj.data.BIMMeshProperties.ifc_definition_id)
+            and tool.Ifc.get().by_id(ifc_id).is_a("IfcRepresentationItem")
+        )
+
     @classmethod
     def is_text_literal(cls, representation: ifcopenshell.entity_instance) -> bool:
         items = ifcopenshell.util.representation.resolve_items(representation)
@@ -1365,3 +1399,7 @@ class Geometry(bonsai.core.tool.Geometry):
         use_immediate_repr = apply_openings and bool(getattr(element, "HasOpenings", None))
         use_immediate_repr = use_immediate_repr or cls.has_material_style_override(element)
         return use_immediate_repr
+
+    @classmethod
+    def get_elements_by_representation(cls, representation):
+        return ifcopenshell.util.element.get_elements_by_representation(tool.Ifc.get(), representation)

src/bonsai/bonsai/tool/loader.py

@@ -879,3 +879,48 @@ class Loader(bonsai.core.tool.Loader):
                 float(props.blender_x_axis_ordinate),
             )
         return Matrix(matrix.tolist())
+
+    @classmethod
+    def convert_geometry_to_mesh(cls, geometry, mesh: bpy.types.Mesh, verts=None) -> bpy.types.Mesh:
+        if verts is None:
+            verts = geometry.verts
+        if geometry.faces:
+            num_vertices = len(verts) // 3
+            total_faces = len(geometry.faces)
+            loop_start = range(0, total_faces, 3)
+            num_loops = total_faces // 3
+            loop_total = [3] * num_loops
+            num_vertex_indices = len(geometry.faces)
+
+            # See bug 3546
+            # ios_edges holds true edges that aren't triangulated.
+            #
+            # we do `.tolist()` because Blender can't assign `np.int32` to it's custom attributes
+            mesh["ios_edges"] = list(set(tuple(e) for e in ifcopenshell.util.shape.get_edges(geometry).tolist()))
+            mesh["ios_item_ids"] = ifcopenshell.util.shape.get_representation_item_ids(geometry).tolist()
+
+            mesh.vertices.add(num_vertices)
+            mesh.vertices.foreach_set("co", verts)
+            mesh.loops.add(num_vertex_indices)
+            mesh.loops.foreach_set("vertex_index", geometry.faces)
+            mesh.polygons.add(num_loops)
+            mesh.polygons.foreach_set("loop_start", loop_start)
+            mesh.polygons.foreach_set("loop_total", loop_total)
+            mesh.polygons.foreach_set("use_smooth", [0] * total_faces)
+            mesh.update()
+
+            # TODO: geometry id is not always an int.
+            rep_id = geometry.id
+            if rep_id.isdigit():
+                if (rep := tool.Ifc.get().by_id(int(rep_id))) and rep.is_a("IfcShapeRepresentation"):
+                    tool.Loader.load_indexed_colour_map(rep, mesh)
+        else:
+            e = geometry.edges
+            v = verts
+            vertices = [[v[i], v[i + 1], v[i + 2]] for i in range(0, len(v), 3)]
+            edges = [[e[i], e[i + 1]] for i in range(0, len(e), 2)]
+            mesh.from_pydata(vertices, edges, [])
+
+        mesh["ios_materials"] = [m.instance_id() for m in geometry.materials]
+        mesh["ios_material_ids"] = geometry.material_ids
+        return mesh